I have had two different motorcycle trailers, both used and both 2008. The Kendon was a dual rail and the Drop Tail is a three rail. I replaced the Kendon for the DropTail. Both trailers are good, but I am finding the DropTail to be a far superior trailer to the Kendon.
So pluses and minuses.
1. The Kendon is 200 pounds lighter than the DropTail.
2. Easier to stand up. One person on the Kendon and two for the DropTail. Although two on both is a good Idea.
3. Kendon has a skinny ramp. I had to walk alongside my ST will running and clutch it up. A little nerve racking. The DropTail has a wide ramp and I can drive up with confidence.
4. Wheel chocks on Kendon locked better to keep the bike from rolling but they were non adjustable for wheel size and never held the bikes upright. The DropTail has locking wheel chocks that are adjustable for wheel size and hold the bike upright while strapping down.
5. The DropTail has many more places to use for tiedowns. More versatile for many different types of bikes.
6. The Kendon had poor tire wear. about 6000 miles and the tires were shot. Also the trailer was very noisy while pulling loaded or unloaded. The Droptail is a much smoother trailer and has larger axle spindles although the same size tires.
7. Once standing up both trailers have different advantages. The Kendon has four casters which makes it really maneuverable. But the floor surface must be fairly smooth. The DropTail has two larger casters and uses the wheels instead of another set of casters. It rolls much easier but needs to be kind of walked back and forth since the wheels do not pivot like casters. I found that not to be a big issue.
8. The newer Kendons do come with a wider loading ramp. But like the one on mine you must find a place to put it. The mounting is underneath the trailer. The DropTail has a wide hydraulic ramp that lowers and raises so there is no secondary storage required.
9. Both trailers store the spare tire underneath the trail. Stupid on both parts. I think that if there was a flat there would be no room to get a jack under the axle. But maybe a small rolling floor jack that I know we all carry with us.

10. The DropTail is slight wider at the axles which allows for a wider bed. The advantage is that when I load two bikes with bags I need not remove the bags for hauling. The Kendon I had to take the bags off the ST or my wife's VFR to haul. Just a bit too narrow.
11. For my purposes and since they were both the same money used. I would recommend the DropTail over the Kendon. And compared to other trailers like the ramp free styles, I am not sure if I want to connect and position the trailer for loading, Disconnect the trailer, Load the bike. Connect the Trailer. Strap the bike down and go.
12. I bought the Kendon without a rockshield and then found one used hoping to resolve damage to the bikes, paint chips and such from the pull vehicle tires and just stuff off the road. Two noticeable things happened, yes the protection for the bikes was better, but it now required for sure two people to standup the trailer and storage in my garage became an issue and secondly and more important tow vehicle MPG dropped by 2 MPG. The DropTail has kind of a flare at the front of the trailer which does a good job of protection for flying debris.
So there it is 12 points of comparison.